Machine for perforating plasterboard



Jan. 7, 1941. E. D. BENI-IAM ETAL MACHINE FOR PERFORATING PLASTERBOARD Filed Sept. 28, 1938 2 Sheets-Sheet l -lnltll ...IIL

I TIUL J We c3606 ATTORNEYJ. v

Jan. 7, 1941. E. D. Bl-:NHAM Erm.

MACHINE FOR PERFORATING PIASTERBOARD Filed Sept. 28. 1938 2 Sheets-Sheet 2 l N I "EN TORS.

Patented Jan. 7, 1941 i l UNITED- sTATEs PATENT OFFICE MACHINE FOR. PERFORATING PLASTER- BOARD l Emmett D. Benham and John R. Rosenleaf, En-

terprise, Kans., assignors to The J. B. Ehrsam & Sons Manufacturing Company, Enterprise, Kans., a corporation of Kansas Application september 2s, 193s, serial No. 232,032 21 claims., (ci. 164-12) The present application relates to a machine for perforating plasterboard, or the like; and is l particularly directed to mechanism for forming wiching a fluent plastic, such as gypsum plaster,

between two fibrous binders, paper being usually used for the binders. The plastic usually takes `a preliminary set very promptly after the composlte sheet is formed; and then. more gradually assumes a permanent and ilnal set. Even after the plastic has assumed its inal set, there is considerable excess moisture in the sheet; and this is removed by a drying operation.

The sheet is usually cut into suitable lengths, before the plastic takes its nal set, although sometimes the material is cut after ithas set. The severed lengths of board are then passed through a drier to expel excess moisture; and after drying, they are stacked into bundles. These bundles of cut lengths are then perforated by drills, usually gang drills, which form the necessary anchoring perforations. Obviously, the drills penetrating through the hard plaster of the Iboards, form a considerable amount of dust; and some quantities of that dust are retained in the rough walls of the perforations. Whemthe boards are then put in place in a building operation, that dust tends to fall out', to the considerable irritation and discomfort of the operator. Furthermore, it has been found in practice that the perforations so formed in some of the boards are likely to be rough and non uniform; and that the paper binders" are likely to betorn in the drilling operation.

It is the primary object of the present invention to provide a machine for perforating plasterboard by punching the board before the plaster takes its iinal set. We are aware of the fact that it has heretofore 4been attempted to provide such a machine and that patents have been issued on machines which are alleged to perform such operation. Some of those machines have been put into commercial use,l however, and have been found to be commercially entirely impracticable for various reasons.

It will be readily appreciated, however, that if a commercially practicable machine for perforat. ing boards prior to the setting of the plaster can be provided, considerable savings may be effected in the production of plasterboard lath. In the first place, it is obvious that considerably less power will be required to punch through a plastic mass retained between paper binders than is required to drill through a corresponding mass of set plaster. In the second place, the drying operation is materially facilitated, shortened, and cheapened if the perforations are formed in the board before the drying step;` since the removal of slugs at frequent intervals throughout the body of the board gives the drying air an enormously larger surface upon which to work. Furthermore, the difficulties with dust, not only in the manufacturing plant but also in the handling of the boards and in the application thereof to building installations, are substantially eliminated.

Still further, the holes formed by punchingA through a plastic mass are found to be considerably more uniform, smoother, and less subject to deformation.

Thus, a further object of the invention is to attain the' above advantages through providing a machine for perforating plasterboard in the unset condition by punching. The present appli-I cation is particularly directed to a machine which will operate to perforate the unset plasterboard before the same is cut into lengths; working upon the unset plasterboard strip as itcontinuously emerges from the forming machine.

lTo the accomplishment of the above and related objects, our invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific construction illustrated and described,.so long as the scope of the appended claims is not violated.

Fig. 1 is a side elevation of a machine constructed in accordance with the present invention;

Fig. 2 is an end elevation thereof, parts being broken away for clarity of illustration;

Fig. 3 is a plan view, thereof, certain parts being shown in horizontal section;

Fig. 4 is a plan, somewhat diagrammatic in character, showing our perforating mechanism and a cut-off machine mounted therewith; and

Fig. 5 is a fragmentalelevation, upon an enlarged scale, of trip mechanisrnlincorporated in the machine.

Referring more particularly to the drawings, it will be seen that the illustrated machine comprises a base indicated generally by the reference numeral I0 upon which is mounted a frame indicated generally by the reference numeral I I and including a table I2 over which the unset plasterboard I3 is conducted by live roll conveyors I4, or the like; the board moving in the direction of the arrows in Fig. 1.

Vertically reciprocably mounted for movement in the frame II is a punching head indicated generally by the reference numeral I5 and comprising a gang of punches I6 which may preferably be of the type disclosed in the patent to William J. Ehrsam No. 2,182,744, issue'dDecember 5, 1,939., Said head is supported upon `a. connecting rod or pitman I8 and a connecting rod or pitman I9. As is clearly shown in Fig. 2, the upper ends of said connecting rods are journaled, as at 29 and 2i, upon trunnions carried by the head I5, while the lower end of said connecting rods are journaled, as at 22 and 23, upon trunnions carried by eccentrics 2i and 25 mounted upon a shaft 26 carried in bearings A stripper plate`2'I is positioned between the punches I6 and the table I2 andv is, of course, formed with perforations through which the punches I6 may be projected. Said plate is preferably supported upon a head 28 which, in

turn, is supported by rods 29 and 30 threaded at their upper ends for the reception of nuts 3I and 32 supported upon the frame II and carrying sprockets 33 andA 34 conected by a chain 35; so that rotation of the hand wheel 36 associated with the sprocket 34 will effect rotation of both nuts 3l and 32 to elevate or drop the rods 29 and 39 and the head 28 and stripper plate 21. Thereby, the clearance between the stripper plate 2'I and the table '25 may be adjusted to adapt the machine for operation upon various thicknesses of material I3.

The base I Il supports guideways 3l in which the frame I I is slidably mounted for horizontal movement with respect to said base. Said frame is formed, as is clearly shown in Fig. 3, with projecting flanges 38 and 39. The flange 35.

supports a trunnion 49 upon which is journaled one end 42 of a connecting rod or pitman 115;,

and the flange 39 supports an aligned trunnion 4l upon which is journaled the end 43 of a connecting rod or pitman 45. The opposite ends 45 and 4l of said respective connecting rods are journaled upon identical eccentrics carried by a shaft 48 journaled in bearings 63 suitably mounted on the base Ill.

In Fig. 1 we have illustrated a shaft 49 which may be a part of the driving mechanism of the board-forming machine, not shown; and in Fig. 3V we have illustrated a shaft 49 which is journaled in the base I0, and may be driven from any suitable source. The shaft 49 or 49 carries a sprocket 55 which drives, through a chain 5I, a sprocket 52 mounted upon a shaft 53 journaled in bearings 64 suitably mounted upon the base I 9. Said bearings 6d are preferably positioned adjacent the bearings 62, are mounted for sliding movement on the base Ill; and set screws 65 and 66 are provided for holding the bearings 62 and 64 together for simultaneously moving said bearings.

The shaft 53 likewise carries a sprocket 54 which drives, through a chain 55, a sprocket 556 mounted upon a shaft 5l journaled in bearings (il supported on the frame Ill; and said bearings 6l are mounted in juxtaposition to the bearings 63, and screws 88 and 89 are associated with' said bearings 63 and 51 to hold the same together and to shift the same simultaneously with vrespect to the base II).

The shaft 53 carries a gear 58 meshing with a l The machine of the present application is positioned in the standard conveyor line associated with a board-forming machine in advance of the cut-off machine indicated generally by the reference numeral 1G, and is preferably so located that the section of the board I3 which is supported upon the table I2 will have attained a preliminary set. The drive train for the shafts 26 and 48 is so coordinated that, as the punches I6 contact the section of the board supported upon the table I2, the frame II will be moving toward the right, as viewed in Fig. 1, at exactly the speed of the advancing board strip., I3; and that such movement of the frame toward the right at that speed will be continued until the punches I6 have penetrated the board and have been withdrawn from engagement with the board. As thepunches i6 move upwardly afterv withdrawal from the board, the movement of the frame II toward the right will be arrested and the frame II will be returned, by movement toward the left, to starting position so that, as the punches again descend into contact with a fresh section of the board, the frame can again begin to move toward the right at thespeed of the advancing board strip.

Preferably, the gears 58 and 59 and the gears and 6I are eccentric gears so that both the punch head I5 and the frame II will be moved at cyclically variable speeds.

As is clearly shown in Fig. 3, the shaft 53 carries a sprocket 'II which, through a chain 'I2, drives a much larger sprocket 'I3 carried upon shaft F4 suitably journaled in the machine frame. As is more particularly shown in Figs. 1 and 5, one end of the shaft I4 is supported in a bearing 'I5 carried by the machine frame. Outboard beyond the bearing l5, the shaft 'I4 carries a short lever I6 which terminates in an actuator cam 11.

Adjacent the lever 'I6 is positioned an arm I8 which, as is shown in Fig. 5, has its lower end 'i9 loosely journaled upon the shaft 14. Alternatively, the lower end of the arm 'I8 may be journaled upon a stationary element, but coaxial with the shaft 14. A

Said arm I8 carries a switch assembly, illustrated more or less diagrammatically by the reference numeral 89. Said switch mechanism comprises a pair of cooperative, normally separated contact elements so arranged that upward movement of the roller 8i will cause said contact elements to be engaged.

' 'I'he switch mechanism 80 is connected in a circuit which controls a cut-off machine indicated generally by the reference numeral I in Fig. 4. Said cut-off machine is of standard construction, and therefore is not illustrated in detail. The arrangement is such that closure of the contact elements of the switch mechanism 80 will cause a single actuation of the cut-olf machine 'I9 to sever the advancing strip of plasterboard.

An advantageous arrangement of perfor-ations once in every eight inches of movement strip.

in plaster lath contemplates the provision of a transverse row or series of perforations in each four inches ,of llength of the lath.y In the illustrated mechanism, the punches I6 are arranged on the punching head I in two series spaced four inches apart; and the4 punching mechanism is so timed as to engage the advancing strip of board of the One advantageous arrangement of the entire illustrated mechanism will provide for cutting the board into fourfoot lengths, the cut-off knife to strike the board midway between two series of perforations. Therefore, the sprockets 1l and 13 are so proportioned that the lshaft 14 makes one revolution upon six revolutions of the shaft 53.

Obviously, in the absence of adjusting means, it would be quite possible for the cut-off machine to get out of step with the perforating mechanism. To accomplish that adjustment, the arm 'I8 is movable through a limited arc about the axis of the shaft 14. The upper end of said arm 18 is formed as a handle 82 and carries-a bolt 83 projecting through an arcuate slot 84 in a plate 86 suitably mounted upon the machine frame. A wing nut 85 `is threadedupon the bolt 83 to clamp the arm 18 in any desired adjusted position.

We claim as our invention:

1. Mechanism for perforating plasterboard of substantial thickness comprising a table, means for continuously advancing a continuous sheet of plasterboard across said table, a vertically operating punch, means for reciprocating said punch to force the same through said board,and nonyielding means for moving said table and punch at the same speed with said board during movev ment' of said punch through the entire thickness strip across said table, means for reciprocatingv said punch perpendicularly with respect tovsaid table to penetrate said strip and to retract said punch therefrom, and non-yielding means for reciprocating said frame on the line of movement of said strip to move said frame with said board and at the same speed therewith throughout penetration and retraction movement of said punch.

3. In combination, punching mechanism includi ing a punch, mechanism for continuously advancing continuously-formed plasterboard orrthe like of substantial, thickness past said punching mechanism, means for reciprocating said'punch to penetrate such plasterboard intermittently and to retract the punch therefrom and non-yielding means operable to prevent movement of said plasterboard with respect to said punching mehanism in the line of feed of said plasterboard throughout penetration and retraction movement of said punch.

4. The combination with means for continuously producing plasterboard` or the like' in a continuous strip of substantial thickness and means for continuously advancing' such strip, of a table disposed in the path of such strip and adapted to support a portion thereof, a punch associated with said table and mounted 4for rectilinear movement with respect thereto to' penetrate that section of said strip supported on said table, means for reciprocating said punch to effect such rectilinear movement, and simultaneously operating non-yielding means for intermittently shifting said table and punch in the direction of movement of said strip to move at the same speed with said strip during engagement of said punch with said strip.

5. In combination, a base, a frame slidably mounted on said base, a punch reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on -said shaft, a pitman connecting said eccentric with said frame, means for driving said shaft, a second shaft journaled 'on said base, a second eccentric on said shaft,`

a second pitman connecting said second eccentric with said punch, and means for driving) `1said second shaft.l

6. In combination, a base, a frameslidably mounted on said base,v a` punch -reciprocablymounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, means .for driving said shaft, a second shaft journaled on said base, a second eccentric on 'said shaft, a

second pitman connecting said second eccentric,

with said punch, and means for driving said second shaft in synchronism with said first shaft.

7'. In combination, a base, a frame slidably mounted on said base, a punch -reciprcoably mountedin said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, means for driving said'shaft at cyclically varying speeds, a second shaft journaled on said base, a second eccentric on said shaft, a second ,pitman connecting said second eccentric with said punch, and means for driving said second shaftat cyclically varying speeds.

8. In combination, a base, a frame slidably mounted on said base, a' punch reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric With said frameeccentric gear means for driving said shaft, a second shaft journaled on said base,- a second eccentric on said shaft, a second pitman connecting said second eccentric with said punch, and eccentric-gear means for driving said' second shaft.

9. In combination, a base, aframe slidably mounted on said base, a punch reciprocablyl mounted in said frame, a shaft journaled 'onr said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, eccentric-gearmmeans for driving said shaft at cyclically varying speeds to reciprocate Said frame on said base in the line of movement of material to be perforated, a second shaft journaled on said base, a second eccentric on said shaft, a second pitmaln connecting said second eccentric with said punch, and eccentric-gear means for driving said second shaft at cyclically varying speeds coordinated with the frame-shifting means to engage said punch with material to be perforated only during periods when the frame is synchronized with such -rnatferial.

10. Mechanismfo'r producingl perforated plaster vlath in predetemnined lengths, comprising punch mechanism operating periodically to perforate an advancing strip of plasterboard, a cutoif machine arranged to receive the board leav- "ing such punching mechanism, and means actuated periodically by the operation of said punchlng mechanism to operate said cut-off machine to sever the advancing strip.

11. In combination, 'means for continuously advancing a continuous strip of plasterboard or the like, a punching mechanism positioned in the path of the advancing strip, a cut-off machine positioned in the path of the advancing strip beyond said punching mechanism, means for driving said punching mechanism to perforate `the strip at predetermined intervals, and means actuated by said last-named means for controlling operation of said cut-off machine.

12. In combination, means for continuously advancing a continuous strip of plasterboard or the like, a punching mechanism positioned in the path of the advancing strip, a cut-off machine positioned in the path of the advancing strip beyond said punching mechanism, means for driving said punching mechanism to perforate the strip at predetermined intervals, electrically-actuated means controlling operation of said cutoff machine, a shaft driven by said punchingmechanism-driving means, and switch means dominating said electrically-actuated means, said shaft being operative, upon rotation, to actuate said switch.

13. In combination, means for continuously advancing a continuous strip of plasterboard or the like, a punching mechanism positioned in the path of the advancing strip, a cut-off machine positioned in the path of the advancing strip beyond said punching mechanism, means for driving said punching mechanism to perforate the strip at predetermined intervals, electricallyactuated means controlling operation of said cut-off machine, a switch dominating said electrically-actuated means, a shaft driven by said punching-mechanism-driving means, an element adjustable about the axis of said shaft and carrying said switch, and cam means carried by said shaft and operable, upon rotation of said shaft, to actuate said switch.

14. In combination, a base, a frame slidably mounted on said base, a head reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, means for driving said shaft, a second shaft journaled on said base, a second eccentric on said shaft, a second pitman connecting said second eccentric with said head, shearing means carried by. said head, and lmeans for driving said second shaft.

15. In combination, a base, a frame slidably mounted on said base, shearing means reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, means for driving said shaft at cyclically varying speeds, a second shaft journaled on said base, a second eccentric on said shaft, a second pitman connecting said second eccentric with said shearing means, and means for driving said second shaft at cyclically varying speeds.

16. In combination, a base, a frame slidably mounted on said base, shearing means reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, eccentric-gear means for driving said shaft, a second shaft journaled on said base, a second eccentric on said shaft, a second pitman connecting said second eccentric with said shearing means, and eccentric-gear means for driving said second shaft.

17. In combination, a base, a frame slidably mounted on said base, shearing means reciprocably mounted in said frame, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, eccentric-gear means for driving said shaft at cyclically varying speeds to reciprocate said frame on said base in the line of movement of material to be sheared, a second shaft journaled on said base, a second eccentric on said shaft, a second pitman connecting said second eccentric with said shearing means, and eccentric-gear means for driving said second shaft at cyclically varying speeds coordinated with the frame-shifting means to engage said shearing means with material to be sheared only during periods when the frame is synchronized with such material.

18. The combination with means for continuously producing plasterboard or the like in a continuous strip of substantial thickness and means for continuously advancing such strip, of a head positioned for cooperation with such strip and mounted for rectilinear movement in a plane substantially perpendicular to the plane of movement of such strip, means for reciprocating such head to effect such rectiliner movement, simultaneously operating means for intermittently shifting said head in the direction of movement of said strip at the same speed with said strip,

and board-penetrating means carried by said head and engageable with said strip to penetrate the entire thickness of said board and be retracted therefrom only during such movement of said head at the same speed with such strip.

19. The combination with means for continuously producing plasterboard or the like in a continuous strip and means for continuously advancing such strip, of a base, a frame slidably mounted on said base for movement in the plane of movement of said strip, a head reciprocably mounted in said frame for movement in a direction substantially perpendicular to the movement of said strip, board-penetrating means carried by said head, a shaft journaled on said base, an eccentric on said shaft, a pitman connecting said eccentric with said frame, eccentric-gear means for driving said shaft at cyclically varying speeds to reciprocate said frame on said kbase in the plane of movement of said strip, a second shaft journaled on said base, a second eccentric on said shaft, a second pitman connecting said eccentric with said head, eccentric-gear means for driving said second shaft at cyclically varying speeds coordinated with the `frame shifting means' to engage said board-penetrating means with such strip only duringperiods when the frame is synchronized with such strip.

20. Mechanism for producing perforated plaster lath in predetermined lengths, comprising a punch operating periodically to perforate an advancing Vstrip of plasterboard, cut-oil` mechanism positioned beyond said punch, and means actuated periodically by the operation of said punch to operate saidv cut-oil' mechanism to sever therv advancing strip.' l

21. Mechanism for producing perforated plaster lath in predetermined lengths, comprising punch mechanism operating periodically to perforate an advancing strip of plasterboard, a severing knife, and means actuated periodically by the operation of said punching mechanism to operate said knife to vsever the advancing strip. y

JOHN R. ROSENLEAF. EMME'ITD. BENHAM. 

